Conventionally, relocation is triggered by a UE measurement report. A radio network controller (RNC) determines whether or not to perform a handover or relocation based on analysis of the UE measurement report.
In a HNB system, the analysis of the UE measurement report is handled by the HNB. In a typical relocation procedure which is generally referred to as Outband Handover, a UE is relocated from a HNB to a macro NodeB.
In today's HNB system, application scenarios in which a user is relocated increase due to the increase in Home NodeB Gateway (HGW) and lu-h interface. In addition to the conventional relocation triggered by a UE measurement report, there is a need for a relocation which is triggered by a HGW and performed in cooperation with the HNB. For example:
1) When the HGW is reset, it is necessary to inform the HNB to reselect another HGW and relocate an existing user to a macro NodeB or another HNB which is capable of accept the user.
2) When the HGW detects a severe degradation on uplink service quality in the lu-h interface, it is necessary to improve the existing process to trigger the HNB to initiate a relocation process for the call of the user.
3) When a user who is currently being serviced is removed from the access control list by the administrator, the user can be relocated to a macro NodeB.
Therefore, in the existing lu-h or lu interface, there is no user relocation procedure initiated by an upper layer node.